Exhaust gas discharged from internal combustion engine such as diesel engine contains large amounts of particulates (particulate matter) containing carbon as the main component acting as a cause of environmental pollution. Accordingly the exhaust system of diesel engine and the like is ordinarily provided with a filter to collect the particulates.
For example, as illustrated in FIG. 10, that type of filter adopts a plugged honeycomb structure 150. The plugged honeycomb structure 150 includes: a honeycomb structure 50 having porous partition walls 52 that partition and form a plurality of cells 51; and plugging sections 53 being arranged to plug one end of the two open end sections of each cell 51, and the plugging sections 53 are arranged in a complementary checkered pattern on each of one end face side and the other end face side of the honeycomb structure 50.
As the method for manufacturing the plugged honeycomb structure, there is a known method in which after a film having an adhesive face (hereinafter the film is also referred to as a “mask”) is stuck to one end face of a non-fired honeycomb structure, and a hole is opened at a portion of the mask covering the cell in which the plugging section is to be arranged, using laser machining utilizing an image processing, or the like, an end portion to which the mask is stuck is immersed in a slurry for plugging, the slurry for plugging is filled and dried in the end portion of the cell, the mask stuck to the end face is peeled, and then the honeycomb structure is fired. (For example, refer to Patent Document 1.)    [Patent Document 1] JP-A 2006-297900